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Finding the Fourth Proportional to 991.17, 1,486.89 and 341.78

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Solution

The fourth proportional to 991.17, 1,486.89 and 341.78 is: 512.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.17 : 1,486.89 = 341.78 : x
  2. Step 2: Convert to fraction form
    991.17/1,486.89 = 341.78/x
  3. Step 3: Cross multiply
    991.17x = 1,486.89 × 341.78
  4. Step 4: Simplify right side
    991.17x = 508,181.83
  5. Step 5: Solve for x
    x = 508,181.83/991.17
  6. Step 6: Final answer
    x = 512.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.